{
  //二进制
  console.log('B',0B111110111);
  //八进制
  console.log(0o767);
}

{
  console.log('15',Number.isFinite(15));
  //15 true  是否有尽
  console.log('NaN',Number.isFinite(NaN));
  console.log('1/0',Number.isFinite('true'/0));
  //是否无穷
  console.log('NaN',Number.isNaN(NaN));
  //NaN true
  console.log('0',Number.isNaN(0));

}

{
  // 是否是整数
  console.log('25',Number.isInteger(25));
  //25 true
  console.log('25.0',Number.isInteger(25.0));
  //25.0 true
  console.log('25.1',Number.isInteger(25.1));
  //25.1 false
  console.log('25.1',Number.isInteger('25'));
//  25.1 false
}

{
  console.log(Number.MAX_SAFE_INTEGER,Number.MIN_SAFE_INTEGER);
  //9007199254740991 -9007199254740991   最大值，最小值
  //   是否在两个数字之间，并且是整数
  console.log('10',Number.isSafeInteger(10));
  //10 true
  console.log('a',Number.isSafeInteger('a'));
//  a false
}

{
  // 截断取整
  console.log(4.1,Math.trunc(4.1));
  //4.1 4
  console.log(4.9,Math.trunc(4.9));
//  4.9 4
}

{
  //  判断一个数字或者数字型字符串是正数1还是负数-1还是0
  console.log('-5',Math.sign(-5));
  //-5 -1
  console.log('0',Math.sign(0));
  //0 0
  console.log('5',Math.sign(5));
  //5 1
  console.log('50',Math.sign('50'));
  //50 1
  console.log('foo',Math.sign('foo'));
//  foo NaN
}


{
  // 立方根
  console.log('-1',Math.cbrt(-1));
  //-1 -1
  console.log('8',Math.cbrt(8));
//  8 2
}
